JP2022074008A - Treprostinil monohydrate crystals and methods for preparation thereof - Google Patents

Abstract

To provide crystalline treprostinil monohydrates of high usefulness.SOLUTION: The present invention provides novel crystalline forms of treprostinil monohydrate, a mixture comprising the same, and preparation methods thereof.SELECTED DRAWING: Figure 5

Description

The present invention generally relates to the solid form of the benzinden prostacyclin derivative, in particular to novel crystal forms of treprostinil monohydrate and methods for producing the same.

Treprostinil (UT15) is a synthetic analog of benzinden prostacyclin and has the following structure:

Treprostinil is used to treat patients with pulmonary arterial hypertension (PAH) for the purpose of improving athletic performance, can be produced in various dosage forms of pharmaceuticals, and can be administered orally, inhaled or injected. Patent Document 1 reveals that inhaled Tyvaso® is a long-acting pulmonary vasodilator that provides significantly lower plasma levels for the treatment of pulmonary hypertension. Remodulin® injection is another formulation approved by the US Food and Drug Administration (FDA) for the treatment of PAH. Remodulin® is a sterile sodium salt formulated for subcutaneous or intravenous administration. Patent Document 2 describes that oral administration of treprostinil / diethanolamine can enhance the oral bioavailability and circulating concentration of treprostinil. Patent Documents 3 and 4 also describe the treatment of pulmonary hypertension by inhalation of treprostinil.

Treprostinyl is a highly polar compound containing one carboxylic acid (-COOH) and two hydroxyl (-OH) functional groups, which is very easily esterified with an alcohol containing treprostinyl itself and is a dimer or ester thereof. Form. Patent Document 5 describes the production of anhydrous treprostinil crystals (Lot No. 01 A07002) for comparison. Anhydrous treprostinil crystals initially contain 0.5% treprostinil dimer (0.2% 750W93 + 0.3% 751W93), which may be produced during the high temperature manufacturing process. Patent Document 5 also states that dimers continue to form in anhydrous treprostinil left at 25 ° C in stability tests, and that dimer formation increases at higher temperatures and is negligible at 5 ° C. Is described. Therefore, Patent Document 5 provides treprostinil monohydrate crystals. Compared with anhydrous treprostinil crystals, treprostinil monohydrate crystals are more stable and can be stored at room temperature for a long period of time. According to the accelerated stability test (lot number 01M07033) for 6 months at 25 ° C, 30 ° C and 40 ° C, the dimer formation of treprostinil monohydrate crystals is almost negligible. However, the esterification impurities of treprostinil are thought to be produced during the crystallization of treprostinil monohydrate by using an alcohol solvent. Treprostinyl monohydrate crystals (lot number D-1007-089, vessel 2) made from an ethanol-aqueous system with a purity of about 99.5% were first described in Patent Document 5. It contains 2% treprostinyl ethyl ester or UT-15 ethyl ester, 0.1% 750W93, 0.04% 751W93 and 0.05% impurity 1 and <0.05% impurity 2. Treprostinil monohydrate crystals (lot number 01M07033) with a purity of about 99.6% were first described in Patent Document 5 with 0.1% 3AU90, 0.2% treprostinil ethyl ester. Alternatively, it contains UT-15 ethyl ester, 0.08% 750W93 and <0.05% 751W93.

In connection with the above problems, Patent Documents 6 and 7 are alternative methods for producing treprostinil monohydrate by using a solvent other than ethanol to avoid the formation of treprostinil ethyl ester. Is disclosed. Patent Document 6 and Patent Document 7 further describe two crystal forms (type A and type B) of treprostinil monohydrate, as shown in FIGS. 1 and 3, respectively. However, the process for producing treprostinil monohydrate A-type crystals and B-type crystals is complicated. Treprostinil monohydrate type A crystals are made from slurry specimens, including 500 mg treprostinil and 3.0 mL of 1,4-dioxane / water = 1/1 (v / v) solution, which is on the wheel. The solids need to be isolated by filtration at room temperature for a long period of time (about 3 days). The solid is then graded into smaller pieces for further drying (about 1 day) to give treprostinil monohydrate type A crystals. Treprostinil monohydrate type B crystals are also produced from slurry specimens (containing 1019 mg treprostinil with 3.5 mL methanol and 3.5 mL water), which are capped at room temperature for a long period of time (about 3 days). It is necessary to put it in a vial and filter it to isolate the solid. The solid is then graded into smaller pieces and further dried (about 44 hours) to give treprostinil monohydrate B-type crystals. After drying for about 2 days, the water content of the treprostinil monohydrate type B crystals is still 12.24%. The water content of treprostinil monohydrate type B crystals does not easily decrease to about 4.41% (1 mol of water molecules in treprostinil is calculated to be 4.41% by weight). The production methods described in Patent Documents 6 and 7 can obtain treprostinyl monohydrate A-type crystals and B-type crystals with less impurities, but these complicated production processes are suitable for industrial scale operations. Is not suitable.

Therefore, there is a need to produce treprostinil monohydrate crystals in an efficient and economical manner, in which case unwanted impurities can be effectively avoided during the production process.

US Patent Application Publication No. 2015/148414 US Pat. No. 82232316 US Pat. No. 6,521,212 US Pat. No. 6756033 International Publication No. 2009/137066 US Pat. No. 9822057 US Pat. No. 10167247

J. Org. Chem. 69,1890-1902 (2004)

From the above, the present inventor conducted a series of experiments and, surprisingly, found that treprostinil monohydrate crystals can be obtained accurately and easily by adding phosphoric acid to a basic treprostinil aqueous solution. This method is relatively short (4-6 hours) without the use of organic solvents (eg alcohols) that can dramatically reduce the potential for formation of treprostinil dimers and / or unwanted esterified impurities. ), It can be carried out at room temperature. The resulting high yield (> 90%) and high purity (> 99%) treprostinil monohydrate crystals can also be easily filtered and dried.

In one aspect, the invention provides two novel crystalline forms of treprostinil monohydrate, "types I and II", and methods of making them.

In one embodiment, the present invention provides a method for producing crystalline treprostinyl monohydrate type I, which provides a basic treprostinyl aqueous solution; the pH of the basic treprostinyl aqueous solution has a pH decrease rate of about 0. It comprises the step of adding phosphoric acid until the pH is about 2 to about 6 acidic at less than 2 / min; and the step of stirring until a precipitate is formed. This method further comprises the step of isolating crystalline treprostinyl monohydrate type I by filtering out the precipitate and / or adding water to rinse the precipitate, and optionally crystalline treprostinyl monohydrate. Includes a step of drying type I.

In one embodiment, the invention is X-ray powder diffraction (XRPD) showing two strongest characteristic peaks at the following 2θ reflection angles: 5.43 ± 0.2 ° and 10.87 ± 0.2 °. A type I crystal of treprostinil monohydrate having a pattern is provided. This crystalline treprostinil monohydrate type I is substantially free of other crystalline treprostinil.

In one embodiment, the invention has a peak start temperature of 65.9 ± 2 ° C and a peak maximum of 79.2 ± 2 ° C, and a peak start temperature of 123.2 ± 2 ° C and 125 on the other. 1. Provided is a crystalline treprostinil monohydrate type I having a differential scanning calorimetry (DSC) thermogram pattern containing two major endothermic peaks with a peak maximum of 1 ± 2 ° C.

In one embodiment, the present invention provides a method for producing crystalline treprostinyl monohydrate type II, which provides a basic treprostinyl aqueous solution; the pH of the basic treprostinyl aqueous solution has a pH decrease rate of about 0. It comprises the step of adding phosphoric acid until the pH is about 2 to about 6 acidic at> 6 / min; and the step of stirring until a precipitate is formed. This method further comprises the step of isolating crystalline treprostinyl monohydrate type II by filtering out the precipitate and / or adding water to rinse the precipitate, and optionally crystalline treprostinyl monohydration. The step of drying the product type II is included.

In one embodiment, the invention is crystalline treprostinil with an XRPD pattern showing two strongest characteristic peaks at the following 2θ reflection angles: 5.19 ± 0.2 ° and 10.40 ± 0.2 °. Monohydrate type II is provided. Crystalline treprostinil monohydrate type II is substantially free of other forms of treprostinil crystals.

In one embodiment, the invention provides crystalline treprostinil monohydrate type II with a DSC thermogram pattern containing two major endothermic peaks, one with a peak starting temperature of 58.8 ± 2 ° C. and 73. It has a peak maximum of 8.8 ± 2 ° C, the other has a peak start temperature of 123.9 ± 2 ° C and a peak maximum of 125.1 ± 2 ° C.

In another aspect, the invention provides a mixture comprising crystalline treprostinyl monohydrate type I and crystalline treprostinyl monohydrate type II, which has the following 2θ reflection angle: 5.26 ± 0.2. Shows characteristic peaks common to °, 13.20 ± 0.2 ° and 16.25 ± 0.2 °, and belongs to type I 10.65 ± 0.2 ° and 12.20 ± 0.2 °. , I have an XRPD pattern showing separate characteristic peaks at 10.36 ± 0.2 °, 11.61 ± 0.2 ° and 12.60 ± 0.2 ° belonging to type II. A mixture of multiple treprostinil monohydrate crystals comprises at least about 10% type I or at least about 10% type II. Mixtures of multiple treprostinil monohydrate crystals are substantially free of other forms of crystalline treprostinil.

In one embodiment, the present invention provides a method for producing a mixture containing crystalline treprostinil monohydrate type I and crystalline treprostinil monohydrate type II. The production method is a step of providing a basic treprostinyl aqueous solution, in which a pH decrease rate of more than about 0.2 and less than about 0.6 / min is added to the basic treprostinyl aqueous solution to add phosphoric acid to the pH of the aqueous solution. Includes a step of acidifying from about 2 to about 6; and a step of stirring until a precipitate is formed. This method further comprises the step of filtering out the precipitate and / or by adding water to rinse the precipitate to obtain a mixture containing crystalline treprostinyl monohydrate type I and crystalline treprostinyl monohydrate type II. Including the step of isolation.

The X-ray powder diffraction pattern of crystalline treprostinil monohydrate type A is shown. A differential scanning calorimetry (DSC) thermogram pattern of crystalline treprostinil monohydrate type A is shown. The X-ray powder diffraction pattern of crystalline treprostinil monohydrate type B is shown. A differential scanning calorimetry (DSC) thermogram pattern of crystalline treprostinil monohydrate type B is shown. The X-ray powder diffraction (XRPD) pattern of the treprostinil monohydrate type I crystal of the present invention is shown. The differential scanning calorimetry (DSC) thermogram pattern of the treprostinil monohydrate type I crystal of the present invention is shown. The thermogravimetric analysis (TGA) pattern of the crystalline treprostinil monohydrate type I of the present invention is shown. The X-ray powder diffraction (XRPD) pattern of the crystalline treprostinil monohydrate type II of the present invention is shown. The differential scanning calorimetry (DSC) thermogram pattern of the crystalline treprostinil monohydrate type II of the present invention is shown. The thermogravimetric analysis (TGA) pattern of the crystalline treprostinil monohydrate type II of the present invention is shown. The X-ray powder diffraction (XRPD) pattern of the mixture of crystalline treprostinyl monohydrate type I crystal and crystalline treprostinyl monohydrate type II of the present invention is shown.

Detailed description of the invention

As used herein, terms such as "substantially free of other forms of crystalline treprostinil" are 0.5%, 0.4%, 0.3%, 0.2 for the compound or mixture in question. It means that it does not contain% or other forms of crystalline treprostinil in excess of 0.1%.

Preparation of basic treprostinil solution

The aqueous solution of basic treprostinil can be produced by any suitable method. The typical synthetic process of treprostinil is shown in Scheme A below:

Treprostinyl can be hydrolyzed by adding a base such as potassium hydroxide, sodium hydroxide and lithium hydroxide to an organic solvent such as methanol, ethanol, isopropyl alcohol, tetrahydrofuran and acetone with water or in a base buffered aqueous solution. By addition, it can be obtained from the hydrolysis of treprostinyl ester or treprostinylnitrile. After the hydrolysis reaction, the produced treprostinil can be dissolved in an aqueous phase and the residual organic solvent can be removed by extraction or concentration. If a hydrolase is used, the hydrolase can be removed by filtration. The produced aqueous solution containing no organic solvent and hydrolase is a so-called "basic treprostinil aqueous solution" as described above. Depending on the embodiment, the pH value of the basic treprostinil aqueous solution is limited to a value between about 7 to about 14, about 8 to about 13, about 9 to about 12, about 10 to about 11, or about 8 to about 12. Not done.

In one embodiment, basic treprostinil is obtained by dissolving an alkaline salt of treprostinil such as treprostinil sodium, treprostinil potassium and treprostinil lithium, or an amine salt of treprostinil such as treprostinil diethanolamine and treprostinil tromethamine in water. An aqueous solution can be obtained.

In one embodiment, the basic treprostinyl aqueous solution can be obtained by dissolving treprostinyl in an organic solvent such as ethyl acetate and then extracting with a basic aqueous solution such as sodium hydrogen carbonate aqueous solution. Therefore, the separated aqueous phase is collected as an aqueous solution of basic treprostinil.

Acidify an aqueous solution of basic treprostinil to obtain a treprostinil solid.

In prior art such as Patent Document 5 and Non-Patent Document 1, treprostinil obtained by adding hydrochloric acid to an aqueous solution of basic treprostinil is a yellow gum-like solid or a sticky liquid. Therefore, prior art requires the use of organic solvents to extract gum-like or sticky treprostinil suspended in aqueous solution. Surprisingly, the present inventor found that the treprostinyl obtained by adding phosphoric acid to the basic treprostinyl aqueous solution was a white crystalline solid, which was easily filtered out as compared with a gum-like solid or a sticky liquid. And found that it can be dried. The white crystalline solid of treprostinil is a monohydrated form confirmed by thermogravimetric analysis (TGA) and Karl Fischer titration. In addition, the resulting treprostinil monohydrate shows two novel crystalline forms (type I and type II) identified by X-ray powder diffraction (XRPD). The present inventor has also found that a slow rate of addition of phosphoric acid leads to the formation of type I and a rapid rate of addition leads to the formation of type II.

Treprostinil monohydrate type I crystals and their production

In one embodiment, the method for producing crystalline treprostinil monohydrate type I crystal or treprostinil monohydrate type I crystal comprises the following steps:
(A) Step of providing a basic treprostinil aqueous solution;
(B) A step of slowly dropping phosphoric acid into a basic treprostinil aqueous solution until the pH decreases at a rate of less than about 0.2 / min and the pH value becomes acidic at about 2 to about 6.
(C) Step of stirring until a precipitate is formed;
(D) Isolation of crystalline treprostinil monohydrate type I by filtering out the precipitate and / or adding water to rinse the precipitate; and (e) optionally crystalline treprostinil type I. The process of drying.

Depending on the embodiment, the concentration of treprostinyl in the basic treprostinyl aqueous solution is about 0.01 g / mL to about 0.10 g / mL, preferably about 0.02 g / mL to about 0.07 g / mL, more preferably about 0. It may be in the range of .03 g / mL to about 0.05 g / mL, but is not limited thereto. The basic treprostinil aqueous solution can be produced at a temperature in the range of about 0 ° C. to about 60 ° C., preferably about 10 ° C. to about 50 ° C., and more preferably room temperature to about 40 ° C., but the present disclosure is not limited thereto. ..

Depending on the embodiment, phosphoric acid may be produced in the form of an aqueous solution of phosphoric acid. In some embodiments, the phosphoric acid aqueous solution added to the basic treprostinil aqueous solution is produced by adding phosphoric acid to water. The concentration of the aqueous phosphoric acid solution may be in the range of about 0.1 N to about 20 N, preferably about 1 N to about 15 N, more preferably about 5 N to about 10 N, but the present disclosure is not limited thereto. In certain embodiments, the pH value of the treprostinil aqueous solution is adjusted to about 2 to about 6, preferably about 2 to about 5, more preferably about 2 to about 4, by adding an aqueous solution of phosphoric acid. Not limited. The aqueous solution of phosphoric acid can be added to the aqueous solution of basic treprostinil at a temperature in the range of about 0 ° C to about 60 ° C, preferably about 10 ° C to about 50 ° C, and more preferably room temperature to about 40 ° C. Is not limited to this. The rate of decrease in pH of the treprostinil aqueous solution should be controlled to less than about 0.2 / min. The lower limit of the rate of decrease in pH of the treprostinil aqueous solution is not limited herein and may be any suitable predetermined or predetermined value. In some embodiments, the aqueous solution of phosphoric acid is added to the aqueous solution of basic treprostinil for more than about 30 minutes.

In some embodiments, the crystalline treprostinil monohydrate type I precipitate is at a temperature in the range of about 0 ° C to about 60 ° C, preferably about 5 ° C to about 50 ° C, more preferably 10 ° C to about 40 ° C. It can be done, but the disclosure is not limited to this.

In some embodiments, the step of filtering the precipitate comprises washing the precipitate with water. The volume of wash water can be from about 50 mL to about 400 mL, preferably from about 75 mL to about 350 mL, more preferably from about 100 mL to about 300 mL per gram of precipitate, but the disclosure is not limited to this. As a result of using no organic solvent, the resulting crystalline treprostinil monohydrate type I contains no residual organic solvent. The crystalline treprostinyl monohydrate type I containing no residual organic solvent is a slurry sample described in Patent Document 6 and Patent Document 7, or a gum-like solid as produced by Patent Document 5 and Non-Patent Document 1. Alternatively, it can be filtered out very easily as compared to a sticky liquid. The filtered treprostinil monohydrate type I crystals have a low viscosity, can be easily removed from the bucket, and can be dried due to their compact solid characteristics.

In some embodiments, the step of drying the treprostinil monohydrate type I crystals is under reduced pressure of about 0.001 Torr to about 20 torr, preferably about 0.01 Torr to about 10 torr, more preferably about 0.01 Torr to about 1 Torr. It can be done, but the disclosure is not limited to these. The drying step of crystalline treprostinil monohydrate type I can be carried out at a temperature in the range of about 0 ° C. to about 40 ° C., preferably about 5 ° C. to about 30 ° C., more preferably 10 ° C. to room temperature. Disclosure is not limited to these.

The methods provided by the present invention (about 4-6) as compared to the methods of making treprostinil monohydrates described in Patent Documents 6 and 7 (they take about 4 days in a complex crushing step). (Take time) is much simpler and more time efficient. In addition, the possibility of composition of treprostinil dimer and treprostinil esterified impurities can be significantly reduced. Moreover, the crystalline treprostinil monohydrate type I having the granular properties obtained by the present invention is very easy to weigh for filtration, drying and industrial handling.

Identification of treprostinil type I crystals

The present invention provides a novel crystalline treprostinil monohydrate type I. Identification of crystalline treprostinil monohydrate type I was verified by Fourier transform infrared (FTIR) spectroscopy, Karl Fischer titration, and TGA. In one embodiment, a treprostinil monohydrate type I crystal showing a characteristic FTIR peak at about 3513 ± 4 cm ^-1 emphasizes the characteristics of the hydrate, which is a molecular entity with a separate hydrated form of treprostinil. Indicates that. In addition, one molecule of water in treprostinil is calculated to be 4.41% by weight. A water content of about 4.41 ± 1% as measured by Karl Fischer titration and TGA (shown in FIG. 7) confirms the presence of 1 mol of water in the hydrated form of treprostinil. The crystalline treprostinil monohydrate type I obtained by the method of the present invention is essentially in the form of a monohydrate. Crystalline treprostinil monohydrate type I has a purity of at least 99.5%, at least 99.6%, at least 99.7%, at least 99.8% or at least 99.9%, excluding residual solvents. ..

In one embodiment, crystalline treprostinil monohydrate type I shows two strongest characteristic peaks at the following 2θ reflection angles: 5.43 ± 0.2 ° and 10.87 ± 0.2 °: It has an XRPD pattern. In some embodiments, the XRPD pattern is substantially free of peaks characteristic of a 2θ reflection angle of 21.71 ° (strongest peak of type A) or 21.56 ° (strongest peak of type B). In a preferred embodiment, the XRPD pattern further comprises peaks characteristic of the following 2θ reflection angles: 12.30 ± 0.2 °, 16.34 ± 0.2 ° and 20.39 ± 0.2 °. More preferably, the XRPD pattern of crystalline treprostinil monohydrate type I is consistent with FIG. Detailed data on crystalline treprostinil monohydrate type I are shown in Table 1.

In one embodiment, the invention provides crystalline treprostinil monohydrate type I having an XRPD pattern substantially as shown in FIG.

According to the characteristics of XRPD, crystalline treprostinil monohydrate type I is different from the crystalline treprostinil monohydrate types A and B described in Patent Documents 6 and 7. The two strongest characteristic peaks of type I are located at 5.43 ° and 10.87 °, type A 10.36 ° and 21.71 °, type B 20.56 ° and 21.56 °. It is clearly different from the two strongest characteristic peaks. Crystalline treprostinil monohydrate type I does not have the strongest characteristic peaks at either 21.71 ° or 21.56 °, which means that type I is substantially free of type A and type B. Means that. In the present invention, treprostinil monohydrate type I crystals are substantially free of peaks characteristic of 2θ reflection at 21.71 ° or 21.56 °. As used herein, the term "substantially free of characteristic peaks" refers to peaks at 21.71 ° or 21.56 ° in the XRPD pattern of treprostinil monohydrate type I crystals. Means that the intensity is less than 10%, preferably less than 3% of the strongest peak intensity at 10.87 ± 0.2 °. In addition, type A contains two peaks in the range of 5.17 ° and 5.88 ° in the range of 5-7 °, while type I contains 5.43 °, 6.05 ° and in the range of 5-7 °. Includes each of the three peaks at 6.61 °. Type A further contains four peaks at 10.36 °, 11.62 °, 12.59 ° and 13.15 ° in the range of 10-14 °, while Type I has 10 in the range of 10-14 °. It contains three peaks at .87 °, 12.30 ° and 13.19 °. However, type B contains four peaks in the range of 10.66 °, 12.10 °, 12.90 ° and 13.10 ° in the range of 10-14 °, while formation I is in the range of 10-14 °. It contains three peaks at 10.87 °, 12.30 ° and 13.19 °. Type B also has 19.45 °, 19.80 °, 20.17 °, 20.56 °, 20.99 °, 21.22 °, 21.56 °, 22 in the range of 19-23.5 °. It contains 10 peaks of .26 °, 22.91 ° and 23.10 °, but type I is 19.65 °, 20.39 °, 20.74 °, 21.32 °, 21.66 °, Includes 7 peaks of 22.42 ° and 23.26 °. Furthermore, peaks at 10.36 ° belonging to type A and 10.66 ° belonging to type B are not present in the type I XRPD pattern, and type I is an independent crystal morphology free of type A and / or type B. It shows that the type I is different from the type A or the type B. Based on the difference in position and relative intensity from the XRPD peak compared to crystalline treprostinil monohydrate types A and B, the invention is not limited by any theory, but the difference in peaks is sample conditions such as particle size. It is thought that it arises from structural differences, not from. This confirms that crystalline treprostinil monohydrate type I is a novel crystalline form.

In one embodiment, the invention has a peak start temperature of 65.9 ± 2 ° C and a peak maximum of 79.2 ± 2 ° C, and a peak start temperature of 123.2 ± 2 ° C and 125 on the other. 1. Provided is a crystalline treprostinil monohydrate type I having a differential scanning calorimetry (DSC) thermogram pattern containing two major endothermic peaks with a peak maximum of 1 ± 2 ° C. In a preferred embodiment, the invention provides crystalline treprostinil monohydrate type I with substantially the DSC thermogram pattern as shown in FIG.

In one embodiment, the characteristics of DSC of crystalline treprostinil monohydrate type I are described in Patent Documents 6 and 7, crystalline treprostinil monohydrate type A (FIG. 2) and type B (FIG. 4). Different compared to. Type A contains two peaks at about 61.94 ° C and 78.30 ° C, peaks at about 126.26 ° C, and Type B contains two peaks at about 60.08 ° C and 74.79 ° C. It contains a peak at about 125.18 ° C. However, type I has a peak at about 79.24 ° C and only a peak at about 125.11 ° C. The starting temperature (65.85 ° C) of the 79.24 ° C peak for type I is higher than the peak maximum temperature of the 61.94 ° C peak for type A and the 60.08 ° C peak for type B, which is crystalline. It is shown that treprostinil monohydrate type I lacks peaks at 61.94 ° C and 60.08 ° C. The characteristics of each temperature of the peak at about 79.24 ° C and the disappearance of the peak around 60.08 ° C to 61.94 ° C are crystalline treprostinil monohydrate type I and crystalline treprostinil monohydrate type A. And, it contains a unique crystal form compared to type B, indicating that type I is different from type A and type B, and in some embodiments, crystalline treprostinil monohydrate type I is of another form. Substantially free of crystalline treprostinil.

In one embodiment, the treprostinyl monohydrate type I crystal is a slurry standard of treprostinyl monohydrate type A and type B crystals described in Patent Documents 6 and 7, or Patent Document 5 and non-patent. Due to its crystalline properties, it has much better filterability as compared to the gum-like solids or sticky liquids of the treprostinyl monohydrate crystals produced according to Document 1. The advantages of treprostinyl monohydrate type I crystals with good filterability are as follows: (1) While filtering and rinsing treprostinyl monohydrate type I crystals, unnecessary impurities dissolved in the filtrate can be easily removed. (2) Since the filtration time of treprostinyl monohydrate type I crystals is short, impurities generated from the residual solvent can be avoided, and (3) treprostinyl monohydrate type I filtered out. The crystal can be easily dried. Based on the above advantages, the esterified impurities of treprostinil can be easily removed, and the formation of treprostinil dimer can be prevented.

Treprostinil monohydrate type II crystals and their production

In one embodiment, the method for producing crystalline treprostinil monohydrate type II or treprostinil monohydrate type II crystals comprises the following steps:
(A) Step of providing a basic treprostinil aqueous solution;
(B) Phosphoric acid is rapidly added to the basic treprostinil aqueous solution until the pH value drops at a rate of more than about 0.6 / min and becomes acidic at a pH of about 2 to about 4, where steps are taken. ;
(C) Step of stirring until a precipitate is formed;
(D) A step of isolating crystalline treprostinil monohydrate type II by filtering out the precipitate and / or adding water to rinse the precipitate;
(E) A step of optionally drying crystalline treprostinil monohydrate type II.

Depending on the embodiment, the concentration of treprostinyl in the basic treprostinyl aqueous solution is about 0.01 g / mL to about 0.10 g / mL, preferably about 0.02 g / mL to about 0.07 g / mL, more preferably about. It may be in the range of 0.03 g / mL to about 0.05 g / mL, but is not limited thereto. The basic treprostinil aqueous solution can be produced at a temperature in the range of about 0 ° C. to about 60 ° C., preferably about 10 ° C. to about 50 ° C., and more preferably room temperature to about 40 ° C., but the present disclosure is not limited thereto. ..

Depending on the embodiment, phosphoric acid may be produced in the form of an aqueous solution of phosphoric acid. In some embodiments, the phosphoric acid aqueous solution added to the basic treprostinil aqueous solution is produced by adding phosphoric acid to water. The concentration of the aqueous phosphoric acid solution may be in the range of about 0.1 N to about 20 N, preferably about 1 N to about 15 N, more preferably about 5 N to about 10 N, but the present disclosure is not limited thereto. In certain embodiments, the pH value of the treprostinil aqueous solution is adjusted to about 2 to about 6, preferably about 2 to about 5, more preferably about 2 to about 4, by adding an aqueous solution of phosphoric acid. Not limited. The aqueous solution of phosphoric acid can be added to the aqueous solution of basic treprostinil at a temperature in the range of about 0 ° C to about 60 ° C, preferably about 10 ° C to about 50 ° C, more preferably room temperature to about 40 ° C. Is not limited to these. The rate of decrease in pH of the treprostinil aqueous solution should be controlled to exceed about 0.6 / min. The upper limit of the rate of decrease in pH of the treprostinil aqueous solution is not limited herein and may be any suitable predetermined or predetermined value. In some embodiments, the aqueous phosphoric acid solution is added to the aqueous solution of basic treprostinil within about 1 to about 10 minutes.

In some embodiments, the precipitate of treprostinil monohydrate type II crystals is at a temperature in the range of about 0 ° C to about 60 ° C, preferably about 5 ° C to about 50 ° C, more preferably 10 ° C to about 40 ° C. This may be done, but the disclosure is not limited to these.

In some embodiments, the step of filtering the precipitate comprises using water to wash the precipitate. The volume of wash water can be from about 50 mL to about 400 mL, preferably from about 75 mL to about 350 mL, more preferably from about 100 mL to about 300 mL per gram of precipitate, but the disclosure is not limited to this. As a result of using no organic solvent, the resulting treprostinil monohydrate type II crystals do not contain any residual organic solvent. The treprostinyl monohydrate type II crystal containing no residual organic solvent is a gum-like solid or adhesive produced by the slurry standard described in Patent Document 6 and Patent Document 7, and Patent Document 5 and Non-Patent Document 1. Very easily filtered as compared to liquids. The filtered treprostinil monohydrate type II crystals have a low viscosity, can be easily removed from the bucket, and can be dried due to their compact solid characteristics.

In some embodiments, the step of drying treprostinil monohydrate type II crystals is under reduced pressure of about 0.001 Torr to about 20 Torr, preferably about 0.01 Torr to about 10 Torr, more preferably about 0.01 Torr to about 1 Torr. It can be done, but the disclosure is not limited to these. The drying step of the treprostinil monohydrate type II crystal can be carried out at a temperature in the range of about 0 ° C. to about 40 ° C., preferably about 5 ° C. to about 30 ° C., more preferably 10 ° C. to room temperature. Is not limited to this.

The novel method provided by the present invention (about 4) as compared to the methods for producing treprostinil monohydrate disclosed in Patent Documents 6 and 7 (they take about 4 days in a complicated crushing step). (Takes up to 6 hours) is much simpler and more time efficient. In addition, this method can significantly reduce the possibility of producing treprostinil dimer and treprostinil esterified impurities. Moreover, the treprostinil monohydrate type II crystals with the granular properties obtained by the present invention are much easier to filter, dry and weigh for industrial handling.

Identification of crystalline treprostinil monohydrate type II

The present invention also provides a novel crystalline treprostinil monohydrate type II. Identification of crystalline treprostinil monohydrate type II has been confirmed by FTIR spectroscopy, Karl Fischer titration and TGA. In one embodiment, a treprostinil monohydrate type II crystal showing a characteristic FTIR peak at about 3513 ± 4 cm ^-1 emphasizes the characteristics of the hydrate, which is a molecule in which the hydrate form of treprostinil is distinct. Indicates that it is an entity. In addition, one molecule of water in treprostinil is calculated to be 4.41% by weight. In some embodiments, the water content of about 4.41 ± 1% as measured by Karl Fischer titration and TGA (shown in FIG. 10) is that 1 mol of water is present in the hydrated form of treprostinil. To confirm. The crystalline treprostinil monohydrate type II obtained by the method of the present invention is essentially a monohydrated form. Treprostinil monohydrate type II crystals have a purity of at least 99.5%, at least 99.6%, at least 99.7%, at least 99.8%, or at least 99.9%, excluding residual solvents. ..

In one embodiment, crystalline treprostinil monohydrate type II shows two strongest characteristic peaks at the following 2θ reflection angles: 5.19 ± 0.2 ° and 10.40 ± 0.2 °: It has an XRPD pattern. In some embodiments, the XRPD pattern is substantially free of characteristic peaks in the 2θ reflection at 21.71 ° (strongest peak of type A) or 21.56 ° (strongest peak of type B). In a preferred embodiment, the XRPD pattern further comprises peaks characteristic of the following 2θ reflection angles: 11.62 ± 0.2 °, 16.19 ± 0.2 ° and 20.14 ± 0.2 °. More preferably, the XRPD pattern of crystalline treprostinil monohydrate type II is consistent with FIG. Specific data for crystalline treprostinil monohydrate type II are shown in Table 2.

In one embodiment, the invention provides crystalline treprostinil monohydrate type II having an XRPD pattern substantially as shown in FIG.

Crystalline treprostinyl monohydrate type II is a crystalline treprostinyl monohydrate described in Patent Document 6 (US Pat. No. 9822057) and Patent Document 7 (US Pat. No. 10,167,247) according to the characteristics of XRPD. It is different from A-type crystals and B-type crystals. The two strongest characteristic peaks of type II crystals are located at 5.2 ° and 10.4 °, which are the two strongest characteristic peaks of type A at 10.36 ° and 21.71 °. And for type B, they are clearly different compared to the two strongest characteristic peaks at 20.56 ° and 21.56 °. Crystalline treprostinil monohydrate type II is substantially free of characteristic peaks at 21.71 ° or 21.56 °, which means that type II is substantially free of types A and B. means. The term "substantially free of characteristic peaks" refers to the XRPD pattern of treprostinil monohydrate type II crystals with a peak intensity of less than 10% at 21.71 ° or 21.56 °, preferably 10. It means less than 3% of the strongest peak intensity at 40 ± 0.2 °. In addition, type II crystals contain five major peaks at 5.19 °, 10.40 °, 11.62 °, 16.19 ° and 20.14 °, while type A has a range of 5.17 °, It contains 5 major peaks each at 10.36 °, 11.62 °, 19.95 ° and 21.71 °. Type A contains a very strong peak in the range of 19-25 °, while Type II contains a main peak only in 20.14 ° in the range of 19-25 °. In particular, type II contains 21.13 ° peaks that are not present in the type A XRPD pattern, whereas type B has 3 of 5.32 °, 5.92 ° and 6.44 ° in the range of 5-7 °. Although it contains one peak, type II contains only two peaks in the range of 5-7 °, 5.19 ° and 5.93 °. Type B further contains four peaks in the range of 10.66 °, 12.10 °, 12.90 ° and 13.10 ° in the range of 10-14 °, while Type II contains 10 in the range of 10-14 °. It contains four different peaks at .40 °, 11.62 °, 12.61 ° and 13.19 °. Furthermore, peaks at 23.06 ° belonging to type A and 19.45 ° belonging to type B are not present in the type II XRPD pattern, and type II is an independent crystal morphology free of type A and / or type B. It shows that it is different from A type or B type. The present invention is not limited by any theory based on the difference in position and relative intensity from the XRPD peak as compared to the treprostinyl monohydrate type A and type B crystals, but the difference in peaks is such as particle size. It is believed that this is due to structural differences rather than sample conditions, confirming that crystalline treprostinyl monohydrate type II is a novel crystalline form.

In one embodiment, the invention provides crystalline treprostinil monohydrate type II with a DSC thermogram pattern containing two major endothermic peaks, one with a peak starting temperature of 58.8 ± 2 ° C. and 73. It has a peak maximum of 8.8 ± 2 ° C, the other has a peak start temperature of 123.9 ± 2 ° C and a peak maximum of 125.1 ± 2 ° C. In a preferred embodiment, the invention provides crystalline treprostinil monohydrate type II with substantially the DSC thermogram pattern as shown in FIG.

In one embodiment, the characteristics of the crystalline treprostinyl monohydrate type II DSC are the crystalline treprostinyl monohydrate described in Patent Document 6 (US Pat. No. 9,82,257) and Patent Document 7 (US Pat. No. 10,167,247). It is different from the Japanese type A (FIG. 2) and B type (FIG. 4). Type A contains two peaks at about 61.94 ° C and 78.30 ° C, peaks at about 126.26 ° C, and Type B contains two peaks at about 60.08 ° C and 74.79 ° C. It contains a peak at about 125.18 ° C. However, type II has a peak at about 73.79 ° C and only a peak at about 125.10 ° C. The starting temperature of the type II peak at 73.79 ° C is 58.76 ° C. However, the type II DSC thermogram pattern showed no peak at either 61.94 ° C or 60.08 ° C, and the type II treprostinil monohydrate crystal had no peak at 61.94 ° C for type A and B. It means that there is no peak at 60.08 ° C for the mold. Crystalline treprostinil monohydrate type II is characterized by different peak temperatures at about 73.8 ° C and peak disappearance at about 60.08 ° C to 61.94 ° C, crystalline treprostinil monohydrate types A and B. It contains a unique crystal form compared to the type, indicating that it is different from the A type and the B type. In some embodiments, crystalline treprostinil monohydrate type II is substantially free of other forms of crystalline treprostinil.

In one embodiment, the treprostinyl monohydrate type II crystal is a crystalline treprostinyl monohydrate type A and type B slurry standard described in Patent Documents 6 and 7, or Patent Documents 5 and non. It has much better filtering properties due to its crystalline properties as compared to the gum-like solids or sticky liquids of crystalline treprostinyl monohydrate produced according to Patent Document 1. The advantages of treprostinyl monohydrate type II crystals with good filterability are that (1) unnecessary impurities dissolved in the filtrate can be easily removed by filtering and rinsing the treprostinyl monohydrate type II crystals (2). ) Since the filtration time of the treprostinyl monohydrate type II crystals is short, impurities rising from the residual solvent can be avoided, and (3) the filtered treprostinyl monohydrate type II crystals can be easily dried. Is. Based on the above advantages, the esterified impurities of treprostinil can be easily removed, and the formation of treprostinil dimer can be prevented.

Preparation of a mixture of treprostinil monohydrate type I and type II crystals

In the present invention, the rate of decrease in pH adjusted by the addition of phosphoric acid in the production of treprostinyl monohydrate crystals determines whether crystalline treprostinyl monohydrate type I or type II can be obtained. Is the key to. When the rate of decrease in pH is controlled to exceed about 0.6 / min, type II precipitates preferentially. However, when the rate of decrease in pH is controlled to less than about 0.2 / min, type I precipitates preferentially. Mixtures of treprostinil monohydrate type I and type II crystals can be obtained when the rate of pH reduction is controlled from about 0.2 to about 0.6 / min. Other operating conditions for producing a mixture of treprostinil monohydrate type I crystal and type II crystal are the same as those for producing type I or type II, and are therefore omitted. A method for producing a mixture of treprostinil monohydrate type I crystal and type II crystal is shown in Example 7, and the obtained XRPD pattern is shown in FIG. Specific data for treprostinil monohydrate type I and type II crystals mixtures are shown in Table 3.

In some embodiments, the mixture of treprostinyl monohydrate type I crystals and treprostinyl monohydrate type II crystals is 5.26 ± 0.2 °, 13.20 ± 0. For type I and type II crystals. It contains characteristic peaks common to 2 ° and 16.25 ± 0.2 °, at 10.65 ± 0.2 ° and 12.20 ± 0.2 ° belonging to type I crystals, and to type II crystals. It has an XRPD pattern containing characteristic peaks separated into 10.36 ± 0.2 °, 11.61 ± 0.2 ° and 12.60 ± 0.2 ° to which it belongs. In one embodiment, the peaks at 5.26 ± 0.2 °, 13.20 ± 0.2 ° and 16.25 ± 0.2 ° are 5.43 ± 0.2 °, 13.20 ± 0.2. From the overlap of neighboring peaks for type I and type II at ° and 16.34 ± 0.2 °, it is a common characteristic peak for type I and type II crystals, 5.19 ± 0.2 °, Peaks for type II at 13.20 ± 0.2 ° and 16.19 ± 0.2 °. However, in the range of 10-14 °, the appearance of characteristic separation peaks at 10.65 ° and 12.20 ° is associated with type I crystals, and 10.36 °, 11.61 ° and 12.60 °. The peaks in are associated with type II crystals, respectively. Based on these results, the specimen is considered to be a mixture of treprostinil monohydrate type I and type II crystals. The absence of the strongest characteristic peaks at 21.71 ° or 21.56 ° means that the mixture of treprostinil monohydrate type I and type II crystals substantially pars the type A and type B crystals of treprostinil monohydrate. Indicates that it is not included. The mixture of treprostinil monohydrate type I and type II crystals, excluding the residual solvent, is at least 99.5%, at least 99.6%, at least 99.7%, at least 99.8%, or at least 99.9%. Has% purity.

In some embodiments, a mixture of treprostinil monohydrate type I and type II crystals comprises at least about 10% type I or type II. In some embodiments, the mixture of treprostinil monohydrate type I and type II crystals is about 10% to 90% type I and about 90% to 10% type II, or about 20% to 80% type I. And about 80% to 20% of type II, but the disclosure is not limited to these. In some embodiments, the mixture of treprostinil monohydrate type I and type II crystals is substantially free of other crystalline treprostinil.

In one embodiment, a mixture of treprostinyl monohydrate type I crystals and type II crystals is a slurry standard of treprostinyl monohydrate type A crystals and type B crystals as described in Patent Documents 6 and 7. , Or has much better filterability due to its crystalline properties compared to gum-like solids or sticky liquids of treprostinyl monohydrate crystals as produced by Patent Document 5 and Non-Patent Document 1. .. The advantages of a mixture of treprostinyl monohydrate type I and type II crystals with good filterability are as follows: (1) Unnecessary impurities dissolved in the filtrate can be removed from treprostinyl monohydrate type I and type II crystals. The mixture can be easily removed by filtration and rinsing, and (2) the filtration time of the mixture of treprostinyl monohydrate type I crystal and type II crystal is short, so impurities generated from the residual solvent are avoided. It is possible, and (3) the filtered mixture of treprostinyl monohydrate type I crystal and type II crystal can be easily dried. Based on the above advantages, the esterified impurities of treprostinil can be easily removed, and the formation of treprostinil dimer can be prevented.

X-ray powder diffraction (XRPD) analysis: XRPD patterns were collected on a Bruker D2 PHASER diffractometer with a fixed divergence slit and a 1D LYNXEYE detector. The sample (about 100 mg) was placed flat on the sample table. The prepared samples were analyzed over a 2θ range from 4 ° to 40 ° with a step size of 0.02 degrees and a step time of 1 second using CuK _α radiation from a 10 mA and 30 kv power source. CuK _β radiation was removed by a divergent beam nickel filter.

Differential scanning calorimetry (DSC) analysis: DSC thermogram patterns were collected on a TA DISCOVERY DSC25 instrument. The sample was weighed in an aluminum pan with a crimp closed aluminum lid. The prepared samples were analyzed from 25 ° C. to 200 ° C. at a scanning rate of 10 ° C./min under nitrogen flow (about 50 mL / min). The melting temperature and heat of fusion were corrected with indium (In) prior to the measurement.

Thermogravimetric analysis (TGA): TGA thermogram patterns were collected on a TA Q500 instrument. The sample was weighed on a platinum pan. The prepared samples were analyzed from ambient temperature to 500 ° C. at a scanning rate of 10 ° C./min under nitrogen. Both temperature and mass corrections were performed prior to the measurement.

High Performance Liquid Chromatography (UPLC) Analysis: UPLC spectra were collected on a Waters ACQUITY UPLC instrument. The sample is diluted to 1 mg / mL with 50/50 (v / v) acetonitrile / _H2O and the column is Waters BEH C18, 1.7 μm, 2.1 × 150 mm. The mobile phase is a gradient change of 60/40 (v / v) buffer / acetonitrile for 0-10 minutes / 60/40-5 / 95 (v / v) buffer / acetonitrile for 10-20 minutes (curve 6). , 20-25 minutes 5/95 (v / v) buffer / acetonitrile, 25-30 minutes 5/95-0/100 (v / v) buffer / acetonitrile gradient change (curve 6), 30- 0/100 (v / v) buffer / acetonitrile for 35 minutes. The buffer solution is an aqueous solution adjusted to pH 3.0 with trifluoroacetic acid. The flow rate is set to 0.42 mL / min. The column temperature was set to 45 ° C and the sample temperature was set to 25 ° C. The injection solution is 1.5 μL. The operating time was set to 35 minutes and the UV detector was set to 210 nm.

Example 1 Production of "Treprostinil Monohydrate Type I Crystal"

2-(((1R, 2R, 3aS, 9aS) -2-hydroxy-1-((S) -3-hydroxyoctyl) -2,3,3a, 4,9,9a-hexahydro-1H-cyclopenta [b] ] Naphthalene-6-yl) oxy) acetonitrile (1.00 g, 2.7 mmol) is dissolved in 10 mL of 2-propanol, followed by the addition of 4 mL of potassium hydroxide solution (16% w / v) at 80 ° C. Was stirred for 2 hours. The reaction mixture was then slowly cooled to room temperature, the reaction was stopped with hydrochloric acid solution, concentrated to remove 2-propanol, and extracted by adding 30 mL saturated aqueous sodium hydrogen carbonate solution containing 30 mL ethyl acetate. Then, the obtained treprostinil was extracted with a sodium hydrogen carbonate solution (pH value of about 8.3) to form a uniform solution at 20 ° C. Then, a 9N phosphoric acid aqueous solution was slowly added to the basic treprostinyl aqueous solution at a pH decrease rate of about 0.15 / min to make it acidic with a pH value of about 3, and then at 20 ° C. for 1 hour until most of the crystals were precipitated. It was stirred. Then, the obtained precipitated crystals were filtered off, rinsed with 180 mL of water, and then dried under high vacuum (about 0.01 Torr) at 20 ° C. for 2 hours to produce 1.01 g of treprostinil monohydrate type I crystals. Was obtained (yield: 91.9%). The results of XRPD and DSC are the same as those shown in FIGS. 5 and 6, and UPLC analysis of the product shows that the purity is 100.0%. Treprostinil ethyl ester and treprostinil dimer are undetectable and no other impurities are found.

Example 2 Production of "Treprostinil Monohydrate Type I Crystal"

2-(((1R, 2R, 3aS, 9aS) -2-hydroxy-1-((S) -3-hydroxyoctyl) -2,3,3a, 4,9,9a-hexahydro-1H-cyclopenta [b] ] Naphthalene-6-yl) oxy) acetonitrile (1.00 g, 2.7 mmol) is dissolved in 10 mL of 2-propanol, followed by the addition of 4 mL of potassium hydroxide solution (16% w / v) at 80 ° C. Was stirred for 2 hours. Then, the reaction mixture was slowly cooled to room temperature, the reaction was stopped with a hydrochloric acid solution, concentrated to remove 2-propanol, and 25 mL of saturated aqueous sodium hydrogen carbonate solution containing 25 mL of ethyl acetate was added for extraction. The resulting treprostinil was then extracted into a sodium hydrogen carbonate solution (pH value about 8.3) to form a homogeneous solution at 30 ° C. Then, a 7N phosphoric acid aqueous solution was slowly added to the basic treprostinyl aqueous solution at a pH decrease rate of about 0.17 / min to make the pH acidic at about 2.5, and then at 30 ° C. until most of the crystals were precipitated. Stir for hours. Then, the obtained precipitated crystals were filtered off, rinsed with 200 mL of water, and then dried under high vacuum (about 0.01 Torr) at 30 ° C. for 2 hours to obtain 1.03 g of treprostinil monohydrate type I crystals. Was obtained (yield: 93.7%). The results of XRPD and DSC are the same as those shown in FIGS. 5 and 6, and UPLC analysis of the product shows that the purity is 100.0%. Treprostinil ethyl ester and treprostinil dimer are undetectable and no other impurities are found.

Example 3 Production of "Treprostinil Monohydrate Type I Crystal"

2,2'-Azandiyldiethanol 2-(((1R, 2R, 3aS, 9aS) -2-hydroxy-1-((S) -3-hydroxyoctyl) -2,3,3a, 4,9,9a) -Hexahydro-1H-cyclopenta [b] naphthalene-5-yl) oxyacetic acid (1.00 g, 2.0 mmol) is dissolved in 20 mL of saturated sodium hydrogen carbonate aqueous solution (pH value about 8.3) and uniformly at 25 ° C. A solution was formed. Then, a 9N aqueous phosphate solution was slowly added to the basic treprostinyl aqueous solution at a pH decrease rate of about 0.16 / min to make the pH value about 2 acidic, until most of the crystals were precipitated. The mixture was stirred at 25 ° C. for 1 hour. Then, the obtained precipitated crystals were filtered off, rinsed with 180 mL of water, and then dried under high vacuum (about 0.1 Torr) at 25 ° C. for 3 hours to make 0.80 g. Treprostinyl monohydrate type I crystals were obtained (yield: 97.2%). The results of XRPD and DSC were the same as those shown in FIGS. 5 and 6, and the UPLC analysis of the product was pure. Is 100.0%. Treprostinyl ethyl ester and treprostinyl dimer are undetectable and no other impurities are found.

Example 4 Preparation of treprostinil monohydrate type II crystal

2-(((1R, 2R, 3aS, 9aS) -2-hydroxy-1-((S) -3-hydroxyoctyl) -2,3,3a, 4,9,9a-hexahydro-1H-cyclopenta [b] ] Naphthalene-6-yl) oxy) acetonitrile (1.00 g, 2.7 mmol) is dissolved in 10 mL of 2-propanol, then 4 mL of potassium hydroxide solution (16% w / v) is added, and 2 at 80 ° C. Stirred for hours. The reaction mixture was then slowly cooled to room temperature, the reaction was stopped with hydrochloric acid solution, concentrated to remove 2-propanol, and 30 mL of potassium hydroxide solution containing 30 mL of ethyl acetate was added for extraction. Then, the obtained treprostinil was extracted with an aqueous potassium hydroxide solution (pH value of about 14) to form a uniform solution at 20 ° C. After that, a 9N phosphoric acid aqueous solution was rapidly added to the basic treprostinyl aqueous solution at a pH decrease rate of about 1.2 / min to make the pH value about 2, and the pH value was adjusted to about 2, and the pH was adjusted to about 2 at 20 ° C. for 1 hour until most of the crystals were precipitated. It was stirred. Then, the obtained precipitated crystals were filtered off, rinsed with 200 mL of water, and then dried under high vacuum (about 0.01 Torr) at 20 ° C. for 2 hours to obtain 1.03 g of treprostinil monohydrate type II. Crystals were obtained (yield: 93.7%). The results of XRPD and DSC are the same as those shown in FIG. 8, and UPLC analysis of the product in FIG. 9 shows that the purity is 100.0%. Treprostinil ethyl ester and treprostinil dimer are undetectable and no other impurities are found.

Example 5 Preparation of treprostinil monohydrate type II crystal

2-(((1R, 2R, 3aS, 9aS) -2-hydroxy-1-((S) -3-hydroxyoctyl) -2,3,3a, 4,9,9a-hexahydro-1H-cyclopenta [b] ] Naphthalene-6-yl) oxy) acetonitrile (1.00 g, 2.7 mmol) is dissolved in 10 mL of 2-propanol, followed by the addition of 4 mL of potassium hydroxide solution (16% w / v) at 80 ° C. The mixture was stirred for 2 hours. Then, the reaction mixture was slowly cooled to room temperature, the reaction was stopped with a hydrochloric acid solution, concentrated to remove 2-propanol, and 20 mL of sodium hydroxide solution containing 20 mL of ethyl acetate was added for extraction. Then, the obtained treprostinil was extracted with an aqueous sodium hydroxide solution (pH value of about 12) to form a uniform solution at 10 ° C. Then, a 10N phosphoric acid aqueous solution was rapidly added to the basic treprostinyl aqueous solution at a pH decrease rate of about 1.9 / min to make it acidic with a pH value of about 2.5, and 1 at 10 ° C. until most of the crystals were precipitated. Stir for hours. Then, the obtained precipitated crystals were filtered off, rinsed with 250 mL of water, and then dried under high vacuum (about 0.01 Torr) at 25 ° C. for 2 hours to obtain 1.02 g of treprostinil monohydrate type II crystals. Was obtained (yield: 92.8%). The results of XRPD and DSC are the same as those shown in FIG. 8, and UPLC analysis of the product in FIG. 9 shows that the purity is 100.0%. Treprostinil ethyl ester and treprostinil dimer are undetectable and no other impurities are found.

Example 6 Preparation of treprostinil monohydrate type II crystals

(((1R, 2R, 3aS, 9aS) -2-hydroxy-1-((S) -3-hydroxyoctyl) -2,3,3a, 4,9,9a-hexahydro-1H-cyclopenta [b] naphthalene) -5-Il) Oxyacetic acid (1.00 g, 2.4 mmol) was dissolved in 20 mL of a sodium hydroxide aqueous solution (pH value of about 14) to form a uniform treprostinyl aqueous solution at 10 ° C., followed by a basic treprostinyl aqueous solution. A 10N aqueous phosphate solution was rapidly added to the pH at a rate of decrease of about 2.4 / min to make the pH value about 2, and the mixture was stirred at 10 ° C. for 1 hour until most of the crystals were precipitated. The obtained precipitated crystals were filtered off, rinsed with 180 mL of water, and then dried under high vacuum (about 0.1 Torr) at 20 ° C. for 3 hours to obtain 0.97 g of treprostinyl monohydrate type II crystals. (Yield: 97.9%). The XRPD and DSC results are the same as those shown in FIG. 8, and the UPLC analysis of the product in FIG. 9 shows that the purity is 100.0%. Treprostinyl ethyl ester and treprostinyl dimer are undetectable and no other impurities are found.

Example 7 Preparation of a mixture of treprostinil monohydrate type I crystal and type II crystal

(((1R, 2R, 3aS, 9aS) -2-hydroxy-1-((S) -3-hydroxyoctyl) -2,3,3a, 4,9,9a-hexahydro-1H-cyclopenta [b] naphthalene) -5-Il) Oxyacetic acid (1.00 g, 2.4 mmol) was dissolved in 20 mL of sodium hydrogen carbonate solution (pH value about 8.3) to form a homogeneous treprostinyl aqueous solution at 20 ° C., followed by basicity. The pH of the aqueous treprostinyl solution was reduced to about 0.32 / min to make it acidic with a pH value of about 2, and the mixture was stirred at 20 ° C. for 1 hour until most of the crystals were precipitated. Then, the obtained precipitated crystals were filtered off. , Rinse with 200 mL of water and then dried under high vacuum (about 0.1 Torr) at 20 ° C. for 2 hours to give 0.99 g of treprostinyl monohydrate crystals (yield: 90.1%). However, it contains about 60% type I and 40% type II, and is substantially free of crystalline treprostinyl of any other formation. The results of XRPD are shown in Figure 11. UPLC analysis of the product. Indicates a purity of 100.0%. Treprostinyl ethyl ester and treprostinyl dimer are undetectable and no other impurities are found.

Claims (21)

2θ Reflection Angle: Crystalline Treprostinil Monohydrate with X-ray Powder Diffraction (XRPD) Pattern Containing Two Strongest Characteristic Peaks at 5.43 ± 0.2 ° and 10.87 ± 0.2 ° Type I. 1 according to claim 1, wherein the XRPD pattern further comprises peaks characteristic of the following 2θ reflection angles: 12.30 ± 0.2 °, 16.34 ± 0.2 ° and 20.39 ± 0.2 °. Crystalline treprostinil monohydrate type I. The crystalline treprostinil monohydrate type I according to claim 1, wherein the XRPD pattern is substantially shown in FIG. It further has a differential scanning calorimetry (DSC) thermogram pattern containing two major endothermic peaks, one with a peak start temperature of 65.9 ± 2 ° C and a peak maximum of 79.2 ± 2 ° C. The crystalline treprostinil monohydrate type I according to claim 1, wherein the other has a peak start temperature of 123.2 ± 2 ° C. and a peak maximum value of 125.1 ± 2 ° C. The crystalline treprostinil monohydrate type I according to claim 4, wherein the DSC thermogram pattern is substantially shown in FIG. The crystalline treprostinil monohydrate type I according to claim 1, which has a purity of at least 99.8%, excluding the residual solvent. The crystalline treprostinil monohydrate type I according to claim 6, which has a purity of at least 99.9%, excluding the residual solvent. The method for producing crystalline treprostinil monohydrate type I according to claim 1, which comprises the following steps:
A step of providing an aqueous solution of basic treprostinil;
A step of adding phosphoric acid to an aqueous solution of basic treprostinyl until the pH decreases at a rate of less than about 0.2 / min and the pH value becomes acidic at about 2 to about 6; and stirring until a precipitate is formed. Process. The method of claim 8, further comprising the following steps:
The step of isolating the crystalline treprostinil monohydrate type I by filtering the precipitate and / or adding water and rinsing the precipitate; and optionally drying the crystalline treprostinil monohydrate type I. Process. 2θ Reflection Angle: Crystalline treprostinil monohydrate type II with an XRPD pattern containing two strongest characteristic peaks at 5.19 ± 0.2 ° and 10.40 ± 0.2 °. 10. The aspect of claim 10, wherein the XRPD pattern further comprises peaks characteristic of the following 2θ reflection angles: 11.62 ± 0.2 °, 16.19 ± 0.2 ° and 20.14 ± 0.2 °. Crystalline treprostinil monohydrate type II. The crystalline treprostinil monohydrate type II according to claim 10, wherein the XRPD pattern is substantially shown in FIG. It further has a differential scanning calorimetry (DSC) thermogram pattern containing two major endothermic peaks, one with a peak start temperature of 58.8 ± 2 ° C and a peak maximum of 73.8 ± 2 ° C. The crystalline treprostinil monohydrate type II according to claim 10, wherein the other has a peak start temperature of 123.9 ± 2 ° C. and a peak maximum value of 125.1 ± 2 ° C. The crystalline treprostinil monohydrate type II according to claim 13, wherein the DSC thermogram pattern is substantially shown in FIG. The crystalline treprostinil monohydrate type II according to claim 10, which has a purity of at least 99.8% excluding the residual solvent. The crystalline treprostinil monohydrate type II according to claim 15, which has a purity of at least 99.9%, excluding the residual solvent. The method for producing crystalline treprostinil monohydrate type II according to claim 10, which comprises the following steps:
A step of providing an aqueous solution of basic treprostinil;
A step of adding phosphoric acid to an aqueous solution of basic treprostinyl until the pH decreases at a rate of more than about 0.6 / min and the pH value becomes acidic at about 2 to about 6; and stirring is performed until a precipitate is formed. Process. 17. The method of claim 17, further comprising the following steps:
The step of isolating the crystalline treprostinil monohydrate type II by filtering the precipitate and / or adding water and rinsing the precipitate; and optionally drying the crystalline treprostinil monohydrate type II. Process. Includes characteristic peaks common to 5.26 ± 0.2 °, 13.20 ± 0.2 ° and 16.25 ± 0.2 °, 10.65 ± 0.2 ° and 12.20 ± 0 .2 ° contains characteristic separation peaks belonging to type I, 10.36 ± 0.2 °, 11.61 ± 0.2 ° and 12.60 ± 0.2 °, characteristic belonging to type II A mixture of crystalline treprostinyl monohydrate type I and crystalline treprostinyl monohydrate type II, comprising a separation peak and comprising at least about 10% of type I or type II. The mixture according to claim 19, which has a purity of at least 99.8%, excluding the residual solvent. The mixture according to claim 20, which has a purity of at least 99.9%, excluding the residual solvent.

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